title: Metabolic bone disease of prematurity and secondary hyperparathyroidism.
abstract: OBJECTIVE
  To illustrate, via case histories, the importance of laboratory investigations for the early diagnosis and management of metabolic bone disease (MBD).
  
  
  METHODS
  We report three cases of extreme premature infants with MBD.
  
  
  RESULTS
  These three infants had several risk factors for MBD of prematurity: very low birthweight, delayed enteral feeds, cholestatic liver disease, intolerance of fortification, the use of glucocorticoids and diuretics. Serum alkaline phosphatase and parathyroid hormone (PTH) were elevated despite relatively normal calcium and phosphate levels. These parameters were corrected with additional supplementation of calcium, phosphate and vitamin D.
  
  
  CONCLUSIONS
  Infants born extremely prematurely have significant calcium and phosphate depletion by the time they reach full term compared with the normal fetal accretion rate. This is exacerbated if there is poor tolerability to feeds where extra calcium and phosphate could not be added either by additives or via human milk fortifier. Serum calcium and phosphate levels may be normal despite inadequate intake or stores due to the counter-regulatory effect of PTH. In infants at risk of MBD, testing serum alkaline phosphatase, vitamin D and PTH with calcium and phosphate may assist in the monitoring and management of MBD.
authors.affiliation: Department of Neonatology, Royal North Shore Hospital The University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Ashish
authors.initials: A
authors.lastname: Lothe
authors.forename: John
authors.initials: J
authors.lastname: Sinn
authors.forename: Monique
authors.initials: M
authors.lastname: Stone
mesh_terms: D001851:Bone Diseases, Metabolic / Q000097:blood / Q000150:complications* / Q000188:drug therapy*; D002118:Calcium / Q000097:blood / Q000627:therapeutic use; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000097:blood / Q000150:complications* / Q000188:drug therapy*; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000097:blood / Q000188:drug therapy; D008297:Male; D010288:Parenteral Nutrition; D010710:Phosphates / Q000097:blood / Q000627:therapeutic use; D047928:Premature Birth; D012307:Risk Factors; D016896:Treatment Outcome; D014807:Vitamin D / Q000627:therapeutic use
chemical_list: D010710:Phosphates; D014807:Vitamin D; D002118:Calcium